Often, it is not possible or preferable for communications between two nodes in a communication network to involve a direct path between the target node and the source node. Sometimes, it is preferable for communications between two nodes to be sent via a path that includes intermediate nodes. For example, nodes associated with locomotives in a consist may be interconnected in a linear manner and may communicate messages between a target node and a source node via multi-hop routing. Determining which path for a communication from a source node to a target node based upon factors such as bandwidth and the number of hops may increase the speed at which the communication is sent.
One proposed implementation of intra-consist communication is described in U.S. Pat. No. 6,370,119 B1 (“the '119 patent”). The '119 patent is directed to a system and method for determining the optimal path for routing a communication in a communication network between a source node and at least one target node. The determination is based upon an evaluation of the path offering the widest bandwidth in the direction of the data transmission, the lowest additive cost, and the lowest hop count. Each link of the network is associated with a least restrictive cost and an additive cost reflecting selected link characteristics. A path is characterized by a restrictive cost and an additive cost derived from the link costs of its communication links. For a connection to be routed, the system identifies a source node, a target node, and a maximum restrictive cost allowed for routing the connection. All acceptable paths from the source node to all the other nodes of the network are determined and stored. These paths are deemed acceptable and are stored if they have the lowest restrictive cost that allows the routing of the connection and if they have the lowest additive cost and minimum hop count. Finally, from the plurality of stored acceptable paths, the path that originates from the source node and terminates at the destination node is selected as the optimal path to route the connection.
The method and system provided by the '119 patent may be subject to a number of possible drawbacks. For example, the method and system of the '119 patent use a protocol that only identifies an optimal path. It may be advantageous to identify a plurality of acceptable paths between a source node and a target node in the event that an optimal path does not function properly. Further, the method and system provided by the '119 patent evaluate paths only based upon the communication link of the path that has the lowest bandwidth available. That is, the method and system of the '119 patent compare the lowest bandwidth link of two paths, preferring the path whose lowest link bandwidth is higher. It may be advantageous to consider the bandwidth of the entire path to compare paths to one another, rather than comparing the lowest bandwidth of a communication link in each of the paths.
The presently disclosed systems and methods are directed to overcoming one or more of the problems set forth above and/or other problems in the art.